Identify caterpillars

Drinker moth caterpillar ©Tom Marshall

How to identify caterpillars

What is a caterpillar?

A caterpillar is the larval stage of a moth or butterfly. It is the second part of their four-stage life cycle: egg, larva, pupa and adult. Many caterpillars look very different as they grow, so we've described the larger stages of the caterpillar's growth when they're often more obvious. Some are easily spotted on their favourite food plants. Here are some of the species you're likely to see!

Drinker moth

When & where: August-June. A variety of habitats including gardens, but especially damp grassland, marshes and boggy areas.

Description: Up to 7 cm long. Dark and covered with brown hairs and golden speckles. A row of white hairs runs down each side of the body.

Drinker moth caterpillar ©Chris Lawrence

Drinker moth caterpillar ©Tom Marshall

A drinker moth caterpillar resting on a grass stem

Drinker caterpillar © Guy Edwardes/2020VISION

Young drinker caterpillar © Vaughn Matthews

Fox moth

When & where: June-April, most obvious in spring. Often heathland and coastal grassland.

Description: Up to 7 cm long. Hairy, with long dark hairs on the sides of the body and shorter orange hairs on top. Young caterpillars are dark with orange bands.

Fox moth caterpillar ©David Longshaw

Fox moth caterpillar by Tom Hibbert

Fox moth caterpillar by David Longshaw

A young fox moth caterpillar, dark with golden bands across its body

Early instar fox moth caterpillar © Frank Porch

Oak eggar

When & where: August-June. A variety of habitats including grassland, heathland, fens, and hedgerows. Often found crawling across paths in spring.

Description: Young caterpillars in late summer and autumn are small and bluish with orange diamond patterns. More obvious in spring, when caterpillars are large and extremely furry, with long, orange-brown hairs. There are black bands between each body segment, and white dashes on each side.

A large, furry oak eggar caterpillar resting on a plant stem

Oak eggar caterpillar © Tom Hibbert

An oak eggar caterpillar, with long golden-brown hairs and black bands between body sections

Oak eggar caterpillar © Frank Porch

An oak eggar caterpillar resting on a stick

Oak eggar caterpillar © Vaughn Matthews

A young oak eggar caterpillar, dark with pale triangular shapes on top. It doesn't yet have the fluffy appearance they adopt in spring.

Early instar oak eggar caterpillar © Frank Porch

Garden tiger

When & where: August-June. A wide range of habitats including gardens.

Description: Up to 6 cm long. An extremely hairy caterpillar, known as the "woolly bear". Mostly black and ginger, with longer white hairs.

A garden tiger moth caterpillar, ginger and black with long white hairs

Garden tiger caterpillar © Frank Porch

Garden tiger caterpillar ©Amy Lewis

A large and fluffy black and orange garden tiger caterpillar climbs a leaf

Garden tiger caterpillar © Faye Davies

A furry black, ginger and white garden tiger caterpillar curled into a defensive ball

Garden tiger caterpillar © Brian Eversham

Cinnabar

When & where: July-September. Found on ragwort in most grassy habitats.

Description: The caterpillars of this moth are distinctive, with black and yellow stripes - warning predators that they taste terrible. They're easily spotted feeding on ragwort.

Cinnabar moth caterpillar ©Andrew Hankinson

A group of stripy black and orange cinnabar caterpillars chomp on a ragwort plant

Cinnabar caterpillars © Jon Hawkins - Surrey Hills Photography

A stripy black and yellow cinnabar caterpillar on a ragwort plant

Cinnabar caterpillar © Niall Benvie/2020VISION

Elephant hawk-moth

When & where: June-September. A variety of habitats, including gardens. Often where rosebay willowherb is found.

Description: Up to 8.5 cm long. A chunky green or brown caterpillar, with several eyespots at the front end and a spiky 'tail' at the rear.

Elephant hawk-moth caterpillar ©Dawn Monrose

Elephant hawk-moth caterpillar © Tom Hibbert

An elephant hawk-moth caterpillar's face, showing the large fake eye spots that confuse would-be predators

Elephant hawk-moth caterpillar © Vaughn Matthews

An elephant hawk-moth caterpillar sat on someone's hand, after being moved from a busy path

Elephant hawk-moth caterpillar © Tom Hibbert

Privet hawk-moth

When & where: July to September. Widespread in southern England and Wales. Found in a variety of habitats, including gardens.

Description: Up to 8.5cm long. Green and chunky, with purple and white stripes on the body and a black and yellow horn on the rear.

Privet hawk-moth caterpillar ©Roy Bedborough

Puss moth

When & where: June to September. Widespread in a variety of habitats, including parks, gardens and wetlands. They feed on poplars and willows.

Description: Recently hatched caterpillars are tiny and black, with two long, whip-like tails. Older caterpillars are plump and green, with a dark, white-edged 'saddle'. The head is surrounded by a pink patch, with false eyes making it look like a giant face. They still have two thin tails. When they're fully fed and ready to pupate, they turn a purplish colour.

Puss moth caterpillar ©Vaughn Matthews

A puss moth caterpillar clings to a branch with its six real legs and four stubby pro-legs

Puss moth caterpillar © Vaughn Matthews

A fat, green puss moth caterpillar clings to a thin branch

Puss moth caterpillar © Tom Hibbert

Two newly hatched puss moth caterpillars, small and black, each with two long, whip-like tails

Newly hatched puss moth caterpillars © Frank Porch

Mullein

When & where: April-July. A range of open habitats, including gardens. Feeds on mulleins and buddleia.

Description: Distinctive whitish caterpillars, with yellow splodges across the body and large black spots.

A mullein moth caterpillar, covered in yellow splodges and black spots, chomping on the leaf of its host plant

Mullein caterpillar © Frank Porch

Mullein moth caterpillar ©Chris Lawrence

A mullein moth caterpillar, covered in yellow splodges and black spots

Mullein caterpillar © Frank Porch

A close up of a mullein moth caterpillar's yellow face, with a pattern of black spots that looks a little like a sad face emoji

Mullein caterpillar © Frank Porch

Yellow-tail

When & where: August-June. Scrubby habitats including hedgerows, woodland and gardens.

Description: Black with long, greyish-white hairs. On top it has a pair of red lines, with a row of white blotches either side of them. A red line runs along each side. The hairs can be an irritant.

Yellow-tail moth caterpillar ©Chris Lawrence

The caterpillar of a yellow-tail moth, feeding on leaves

Yellow-tail caterpillar © Tom Hibbert

A yellow-tail moth caterpillar feeding on a leaf

Yellow-tail caterpillar © Tom Hibbert

Brown-tail

When & where: August-May. Scrubby habitats, including coastal scrub.

Description: Black with long brown hairs, two red spots on top and a line of white marks along each side. Found in conspicuous communal webs on food plants. The hairs cause skin irritation.

A fully-grown brown-tail moth caterpillar

Brown-tail moth caterpillar © Tom Hibbert

A very young brown-tail moth caterpillar on the silk web in which they live communally

Young brown-tail caterpillar © Chris Lawrence

A brown-tail moth caterpillar, with a line of white stripes each side of its back and two red dots in the centre

Brown-tail caterpillar © Frank Porch

Knot grass

When & where: June-October. Grasslands, wetlands, heathlands, open woodlands, and coastal habitats.

Description: Black with brown hairs. Row of alternating red spots and lines on top, with a line of white dashes either side. Row of spots and dashes on each side. Rests with slight hunch in the back.

The caterpillar of a knot grass moth, crawling along a plant stem

Knot grass caterpillar © Vaughn Matthews

A knot grass caterpillar, with tufts of brown hair and rows of red and white stripes, dots, and dashes

Knot grass caterpillar © Frank Porch

Peacock

When & where: May-July. Common in a range of habitats where common nettle is present.

Description: Up to 4.5 cm. Black with black spines and small white dots. Found in communal webs on common nettles.

A spiky black peacock caterpillar feasts on a nettle leaf

A group of young peacock caterpillars swarm over a nettle leaf

Vapourer

When & where: May-September. Commonly found in a variety of habitats including woodland, parks and gardens.

Description: A funky-looking grey and black caterpillar, with large tufts of hair, including a mohawk of yellow tufts on the back. Large caterpillars can often be spotted in late summer on a range of shrubs and trees.

A vapourer moth caterpillar, covered in thick tufts of hair, crawling across a leaf

A vapourer moth caterpillar rests on a leaf, showing off its variety of colourful tufts of hair

Pale Tussock

When & where: June-October. Found on a wide variety of deciduous trees and other plants, including bramble.

Description: A striking bright green caterpillar, with black bands between its body segments, yellow/whitish hairs, a row of yellow tufts on top and a red tuft at the rear.

A pale tussock caterpillar, lime green with bright yellow tufts and a tufty red tail

A pale tussock caterpillar curled in a defensive posture, revealing the jet black bands between its body segments

Not a caterpillar!

Sawfly larvae

Sawflies are a group of flies, whose larvae look very similar to moth and butterfly caterpillars. The larvae are usually 1-4 cm long, but come in an impressive variety of colours. One way to spot a sawfly larva is to count the legs - they also have six true legs, but usually have six or more pairs of the stumpy 'prologs', whereas caterpillars have five or fewer.